AC30 Handwired 2x12 Combo Mushy and lacking highs

Messages
234
Hello people. So I highjacked another thread and got limited replies so I though I would copy my question over to a new thread where my question can be clear to those reading.

I just got my AC30 handwired last week. I believe my serial number is 438. I'm not sure how many of these have been made, or if these are even still in production, all I know it's that I had to look for 6 weeks just to find one! The wait gave me a sense of nostalgia and a feeling that I was buying a piece of Vox history.

Anyways the amp seems very finicky with somewhat of an inconsistent volume. The amp seems very muddy and mushy in the bass and for such a normally bright amp it's actually not that bright or rich in the top end. I verified that both bright caps are still intact. This is the first tube rectified amp I have played in years since I used to play mostly Mesa amps. My taste in amplifiers and style has changed quite a bit in the last few years, but I don't remember the mesas with tube rectifiers ever being this compressed, which kind of scares me.

I just sold a Vox AC15C1 and have owned an AC30CC2X, so I have a good feeling how the amp "should" sound.

There is some sporadic microphonic noise that I definitely can attribute most likely to the preamp tubes. The subtle fluctuation in volume and mushyness I am at a loss about. The tubes are all Ruby-tubes brdand which is what I think the amp originally shipped with. Of course next time I come across $200, I will re tube the amp.

Do you guys know if there is anything I can look for or have any suggestions of why the amp sounds dull and mushy, or why the volume is inconsistent?

Thanks in advance
 
Last edited:

MogwaiBoy

Member
Messages
3,734
I had an AC30 Hand-Wired Head (same as yours, just in head form, not combo) and I would have never described it as mushy or bassy - and it had the potential for lots of searing, slicing high end... more than most amps I've ever played.

Are you experiencing the same thing on both channels? The Top Boost channel can get crazy amounts of chimey treble, basically too much if you're not careful.

If the volume flickers up and down it's likely a tube problem - which might explain the other negative side-effects. I would take it to a tech to get it looked over. Or if you bought it brand new from the shop, it's still under warranty so just get them to fix or replace it.

You have to remove the whole damn chassis to get at the tubes on the head version - not sure about your combo.
 

Gretsch&Vox

Member
Messages
2,892
Fluctuation in volume tells me the power tubes are wearing or worn out. Put a fresh, matched quartet of JJs. They are very chimey. Celestion Alnico Blues are definitely needed to also bring out the chimes. I think the JJ ECC803S tube is the best, most brilliant preamp tube available.
 

csweet08

Member
Messages
383
Aside from some new tubes, the greenbacks in those aren't going to give you that high end sparkle you get from a blue. I love greenbacks but they don't really do chime
 
Messages
234
Guys, thank you all for your responses.

I will be re_tubing in the next few weeks.

I have had great results using mesa el84`s, an EHX 12at7 in V1 and Mullard 12ax7`s on V2 and V3.

Aside from JJ, what else do you recommend?

Also is there any variance in sag between brands when it comes to GZ34 rectifier tubes?
 

Nelson89

Member
Messages
3,609
Tubes i've always had luck with either JJs or Sovteks in my AC15HW1. But yeh, if you got it second hand, have a tech look over it because i wouldn't really attribute any of those adjectives to that particular line of amps, definitely an issue going on there unless you've got the Tone Cut set all the way clockwise, but i'll assume that's not the issue since you have had experience with Vox's before, that's usually more an issue for non-vox users.

Other than that, greenbacks work ok in those amps if you're after that sound, but the classic vox sound is more about the blues, i switched the speaker in mine to the blue a few months in after the green was broken in and just wouldn't do it for me. Made a hell of a difference.
 

Rumy22

Senior Member
Messages
287
And you must bias new power tubes. If you do not know why or how, consult a tech. You will love your amp afterwards.
 

whitepapagold

Member
Messages
694
Aside from some new tubes, the greenbacks in those aren't going to give you that high end sparkle you get from a blue. I love greenbacks but they don't really do chime
This makes a HUGE difference...

I have a blue and greenback for my JMI15 and the greenback doesn't even come close to the top end of the blue...

But I agree with the other posters that the tubes sound like the initial issue.
 

earthmud

Silver Supporting Member
Messages
3,232
Hello people. So I highjacked another thread and got limited replies so I though I would copy my question over to a new thread where my question can be clear to those reading.

I just got my AC30 handwired last week. I believe my serial number is 438. I'm not sure how many of these have been made, or if these are even still in production, all I know it's that I had to look for 6 weeks just to find one! The wait gave me a sense of nostalgia and a feeling that I was buying a piece of Vox history.

Anyways the amp seems very finicky with somewhat of an inconsistent volume. The amp seems very muddy and mushy in the bass and for such a normally bright amp it's actually not that bright or rich in the top end. I verified that both bright caps are still intact. This is the first tube rectified amp I have played in years since I used to play mostly Mesa amps. My taste in amplifiers and style has changed quite a bit in the last few years, but I don't remember the mesas with tube rectifiers ever being this compressed, which kind of scares me.

I just sold a Vox AC15C1 and have owned an AC30CC2X, so I have a good feeling how the amp "should" sound.

There is some sporadic microphonic noise that I definitely can attribute most likely to the preamp tubes. The subtle fluctuation in volume and mushyness I am at a loss about. The tubes are all Ruby-tubes brdand which is what I think the amp originally shipped with. Of course next time I come across $200, I will re tube the amp.

Do you guys know if there is anything I can look for or have any suggestions of why the amp sounds dull and mushy, or why the volume is inconsistent?

Thanks in advance
Fluctuation in volume tells me the power tubes are wearing or worn out. Put a fresh, matched quartet of JJs. They are very chimey. Celestion Alnico Blues are definitely needed to also bring out the chimes. I think the JJ ECC803S tube is the best, most brilliant preamp tube available.
I agree with Jay(yep I said it!).:aok: When My JJ el84's start to mush out is when I know it's time to replace them. I get about 6-8 months out of a quad. No need to bias just make sure you order a matched quad. Yes Jay, JJ's in my JMJ30! I still prefer NOS but the JJ el84 is a great sounding tube for the price.
 

Gretsch&Vox

Member
Messages
2,892
I agree with Jay(yep I said it!).:aok: When My JJ el84's start to mush out is when I know it's time to replace them. I get about 6-8 months out of a quad. No need to bias just make sure you order a matched quad. Yes Jay, JJ's in my JMJ30! I still prefer NOS but the JJ el84 is a great sounding tube for the price.
:aok
 






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